1. Field of the Invention
The present invention relates to a balloon controller for an endoscopic apparatus and, more particularly, to a balloon controller for controlling a balloon used in an endoscopic apparatus for observing a deep-part digestive tract such as the small intestine or the large intestine.
2. Description of the Related Art
When an insertion portion of an endoscope is inserted into a deep-part digestive tract such as the small intestine, a force for insertion cannot be easily transmitted to the foremost end of the insertion portion due to the existence of complicated bends in the intestinal tract and it is difficult to insert the insertion portion to a deep part, if the insertion portion is simply forced into the tract. For example, if an unnecessary bend or warp is caused in the insertion portion, the insertion portion cannot be inserted to a deeper portion of the tract. A method has therefore been proposed in which the insertion portion of an endoscope is inserted into a body cavity together with an insertion assist implement which caps the insertion portion, and an unnecessary bend or warp in the insertion portion is prevented by guiding the insertion portion with the insertion assist implement.
Japanese Patent Application Laid-Open No. 2002-301019 discloses an endoscopic apparatus in which a first balloon is provided on an insertion portion of an endoscope close to the foremost end of the insertion portion and a second balloon is provided on an insertion assist implement (also referred to as an over tube or sliding tube) close to the foremost end of the insertion assist implement. The first and second balloons can fix the insertion portion and the insertion assist implement in the intestinal tract such as the small intestine by expanding the first and second balloons. This endoscopic apparatus is capable of inserting the insertion portion to a deep portion of an intestinal tract such as the small intestine having complicated bends by alternately inserting the insertion portion and the insertion assist implement while repeating expanding and shrinking the first and second balloons.
Japanese Patent Application Laid-Open No. 2003-144378 discloses a balloon controller which controls supply of air to a balloon and drawing of air from the balloon. In a front face of a main unit of this balloon controller are provided a plurality of display panels, on which a set pressure and a set time at the time of supply or drawing of air are indicated, and a plurality of warning lamps, each of which is lighted when the pressure or time exceeds a set value. When an abnormality occurs, the corresponding warning lamp is lighted to enable an operator to recognize the abnormality.
The balloon controller disclosed in Japanese Patent Application Laid-Open No. 2003-144378, however, is provided with a number of display panels and a number of warning lamps and, therefore, has a problem that the manufacturing cost and size of the controller are increased and a problem that the states of expansion and shrinkage of the balloon and an abnormal condition of the balloon cannot be easily grasped through observation of the display panels and warning lamps.
Further, in the case of application of the balloon controller disclosed in Japanese Patent Application Laid-Open No. 2003-144378 to the double balloon type of endoscopic apparatus Japanese Patent Application Laid-Open No. 2002-301019, the number of display panels and the number of warning lamps are doubled and it is more difficult to accurately grasp conditions.